How much memory does a GameObject consume? (iOS)

I'd like to use GameObjects for organization and grouping (among other purposes, to store components/scripts that don't really "belong" to any specific GameObject, but need to be linked into many scripts).

I shouldn't do this if a GameObject consumes a lot of memory. How much memory is needed by a GameObject that contains a small MonoBehaviour component? (I could try to count the fields and make an estimate, but I don't know c# well enough to do this correctly.)